linux/lib/test_printf.c
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   1/*
   2 * Test cases for printf facility.
   3 */
   4
   5#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   6
   7#include <linux/init.h>
   8#include <linux/kernel.h>
   9#include <linux/module.h>
  10#include <linux/printk.h>
  11#include <linux/random.h>
  12#include <linux/slab.h>
  13#include <linux/string.h>
  14
  15#include <linux/bitmap.h>
  16#include <linux/dcache.h>
  17#include <linux/socket.h>
  18#include <linux/in.h>
  19
  20#include <linux/gfp.h>
  21#include <linux/mm.h>
  22
  23#define BUF_SIZE 256
  24#define PAD_SIZE 16
  25#define FILL_CHAR '$'
  26
  27#define PTR1 ((void*)0x01234567)
  28#define PTR2 ((void*)(long)(int)0xfedcba98)
  29
  30#if BITS_PER_LONG == 64
  31#define PTR1_ZEROES "000000000"
  32#define PTR1_SPACES "         "
  33#define PTR1_STR "1234567"
  34#define PTR2_STR "fffffffffedcba98"
  35#define PTR_WIDTH 16
  36#else
  37#define PTR1_ZEROES "0"
  38#define PTR1_SPACES " "
  39#define PTR1_STR "1234567"
  40#define PTR2_STR "fedcba98"
  41#define PTR_WIDTH 8
  42#endif
  43#define PTR_WIDTH_STR stringify(PTR_WIDTH)
  44
  45static unsigned total_tests __initdata;
  46static unsigned failed_tests __initdata;
  47static char *test_buffer __initdata;
  48static char *alloced_buffer __initdata;
  49
  50static int __printf(4, 0) __init
  51do_test(int bufsize, const char *expect, int elen,
  52        const char *fmt, va_list ap)
  53{
  54        va_list aq;
  55        int ret, written;
  56
  57        total_tests++;
  58
  59        memset(alloced_buffer, FILL_CHAR, BUF_SIZE + 2*PAD_SIZE);
  60        va_copy(aq, ap);
  61        ret = vsnprintf(test_buffer, bufsize, fmt, aq);
  62        va_end(aq);
  63
  64        if (ret != elen) {
  65                pr_warn("vsnprintf(buf, %d, \"%s\", ...) returned %d, expected %d\n",
  66                        bufsize, fmt, ret, elen);
  67                return 1;
  68        }
  69
  70        if (memchr_inv(alloced_buffer, FILL_CHAR, PAD_SIZE)) {
  71                pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote before buffer\n", bufsize, fmt);
  72                return 1;
  73        }
  74
  75        if (!bufsize) {
  76                if (memchr_inv(test_buffer, FILL_CHAR, BUF_SIZE + PAD_SIZE)) {
  77                        pr_warn("vsnprintf(buf, 0, \"%s\", ...) wrote to buffer\n",
  78                                fmt);
  79                        return 1;
  80                }
  81                return 0;
  82        }
  83
  84        written = min(bufsize-1, elen);
  85        if (test_buffer[written]) {
  86                pr_warn("vsnprintf(buf, %d, \"%s\", ...) did not nul-terminate buffer\n",
  87                        bufsize, fmt);
  88                return 1;
  89        }
  90
  91        if (memchr_inv(test_buffer + written + 1, FILL_CHAR, BUF_SIZE + PAD_SIZE - (written + 1))) {
  92                pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator\n",
  93                        bufsize, fmt);
  94                return 1;
  95        }
  96
  97        if (memcmp(test_buffer, expect, written)) {
  98                pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote '%s', expected '%.*s'\n",
  99                        bufsize, fmt, test_buffer, written, expect);
 100                return 1;
 101        }
 102        return 0;
 103}
 104
 105static void __printf(3, 4) __init
 106__test(const char *expect, int elen, const char *fmt, ...)
 107{
 108        va_list ap;
 109        int rand;
 110        char *p;
 111
 112        if (elen >= BUF_SIZE) {
 113                pr_err("error in test suite: expected output length %d too long. Format was '%s'.\n",
 114                       elen, fmt);
 115                failed_tests++;
 116                return;
 117        }
 118
 119        va_start(ap, fmt);
 120
 121        /*
 122         * Every fmt+args is subjected to four tests: Three where we
 123         * tell vsnprintf varying buffer sizes (plenty, not quite
 124         * enough and 0), and then we also test that kvasprintf would
 125         * be able to print it as expected.
 126         */
 127        failed_tests += do_test(BUF_SIZE, expect, elen, fmt, ap);
 128        rand = 1 + prandom_u32_max(elen+1);
 129        /* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
 130        failed_tests += do_test(rand, expect, elen, fmt, ap);
 131        failed_tests += do_test(0, expect, elen, fmt, ap);
 132
 133        p = kvasprintf(GFP_KERNEL, fmt, ap);
 134        if (p) {
 135                total_tests++;
 136                if (memcmp(p, expect, elen+1)) {
 137                        pr_warn("kvasprintf(..., \"%s\", ...) returned '%s', expected '%s'\n",
 138                                fmt, p, expect);
 139                        failed_tests++;
 140                }
 141                kfree(p);
 142        }
 143        va_end(ap);
 144}
 145
 146#define test(expect, fmt, ...)                                  \
 147        __test(expect, strlen(expect), fmt, ##__VA_ARGS__)
 148
 149static void __init
 150test_basic(void)
 151{
 152        /* Work around annoying "warning: zero-length gnu_printf format string". */
 153        char nul = '\0';
 154
 155        test("", &nul);
 156        test("100%", "100%%");
 157        test("xxx%yyy", "xxx%cyyy", '%');
 158        __test("xxx\0yyy", 7, "xxx%cyyy", '\0');
 159}
 160
 161static void __init
 162test_number(void)
 163{
 164        test("0x1234abcd  ", "%#-12x", 0x1234abcd);
 165        test("  0x1234abcd", "%#12x", 0x1234abcd);
 166        test("0|001| 12|+123| 1234|-123|-1234", "%d|%03d|%3d|%+d|% d|%+d|% d", 0, 1, 12, 123, 1234, -123, -1234);
 167        test("0|1|1|128|255", "%hhu|%hhu|%hhu|%hhu|%hhu", 0, 1, 257, 128, -1);
 168        test("0|1|1|-128|-1", "%hhd|%hhd|%hhd|%hhd|%hhd", 0, 1, 257, 128, -1);
 169        test("2015122420151225", "%ho%ho%#ho", 1037, 5282, -11627);
 170        /*
 171         * POSIX/C99: »The result of converting zero with an explicit
 172         * precision of zero shall be no characters.« Hence the output
 173         * from the below test should really be "00|0||| ". However,
 174         * the kernel's printf also produces a single 0 in that
 175         * case. This test case simply documents the current
 176         * behaviour.
 177         */
 178        test("00|0|0|0|0", "%.2d|%.1d|%.0d|%.*d|%1.0d", 0, 0, 0, 0, 0, 0);
 179#ifndef __CHAR_UNSIGNED__
 180        {
 181                /*
 182                 * Passing a 'char' to a %02x specifier doesn't do
 183                 * what was presumably the intention when char is
 184                 * signed and the value is negative. One must either &
 185                 * with 0xff or cast to u8.
 186                 */
 187                char val = -16;
 188                test("0xfffffff0|0xf0|0xf0", "%#02x|%#02x|%#02x", val, val & 0xff, (u8)val);
 189        }
 190#endif
 191}
 192
 193static void __init
 194test_string(void)
 195{
 196        test("", "%s%.0s", "", "123");
 197        test("ABCD|abc|123", "%s|%.3s|%.*s", "ABCD", "abcdef", 3, "123456");
 198        test("1  |  2|3  |  4|5  ", "%-3s|%3s|%-*s|%*s|%*s", "1", "2", 3, "3", 3, "4", -3, "5");
 199        test("1234      ", "%-10.4s", "123456");
 200        test("      1234", "%10.4s", "123456");
 201        /*
 202         * POSIX and C99 say that a negative precision (which is only
 203         * possible to pass via a * argument) should be treated as if
 204         * the precision wasn't present, and that if the precision is
 205         * omitted (as in %.s), the precision should be taken to be
 206         * 0. However, the kernel's printf behave exactly opposite,
 207         * treating a negative precision as 0 and treating an omitted
 208         * precision specifier as if no precision was given.
 209         *
 210         * These test cases document the current behaviour; should
 211         * anyone ever feel the need to follow the standards more
 212         * closely, this can be revisited.
 213         */
 214        test("    ", "%4.*s", -5, "123456");
 215        test("123456", "%.s", "123456");
 216        test("a||", "%.s|%.0s|%.*s", "a", "b", 0, "c");
 217        test("a  |   |   ", "%-3.s|%-3.0s|%-3.*s", "a", "b", 0, "c");
 218}
 219
 220static void __init
 221plain(void)
 222{
 223        test(PTR1_ZEROES PTR1_STR " " PTR2_STR, "%p %p", PTR1, PTR2);
 224        /*
 225         * The field width is overloaded for some %p extensions to
 226         * pass another piece of information. For plain pointers, the
 227         * behaviour is slightly odd: One cannot pass either the 0
 228         * flag nor a precision to %p without gcc complaining, and if
 229         * one explicitly gives a field width, the number is no longer
 230         * zero-padded.
 231         */
 232        test("|" PTR1_STR PTR1_SPACES "  |  " PTR1_SPACES PTR1_STR "|",
 233             "|%-*p|%*p|", PTR_WIDTH+2, PTR1, PTR_WIDTH+2, PTR1);
 234        test("|" PTR2_STR "  |  " PTR2_STR "|",
 235             "|%-*p|%*p|", PTR_WIDTH+2, PTR2, PTR_WIDTH+2, PTR2);
 236
 237        /*
 238         * Unrecognized %p extensions are treated as plain %p, but the
 239         * alphanumeric suffix is ignored (that is, does not occur in
 240         * the output.)
 241         */
 242        test("|"PTR1_ZEROES PTR1_STR"|", "|%p0y|", PTR1);
 243        test("|"PTR2_STR"|", "|%p0y|", PTR2);
 244}
 245
 246static void __init
 247symbol_ptr(void)
 248{
 249}
 250
 251static void __init
 252kernel_ptr(void)
 253{
 254}
 255
 256static void __init
 257struct_resource(void)
 258{
 259}
 260
 261static void __init
 262addr(void)
 263{
 264}
 265
 266static void __init
 267escaped_str(void)
 268{
 269}
 270
 271static void __init
 272hex_string(void)
 273{
 274        const char buf[3] = {0xc0, 0xff, 0xee};
 275
 276        test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
 277             "%3ph|%3phC|%3phD|%3phN", buf, buf, buf, buf);
 278        test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
 279             "%*ph|%*phC|%*phD|%*phN", 3, buf, 3, buf, 3, buf, 3, buf);
 280}
 281
 282static void __init
 283mac(void)
 284{
 285        const u8 addr[6] = {0x2d, 0x48, 0xd6, 0xfc, 0x7a, 0x05};
 286
 287        test("2d:48:d6:fc:7a:05", "%pM", addr);
 288        test("05:7a:fc:d6:48:2d", "%pMR", addr);
 289        test("2d-48-d6-fc-7a-05", "%pMF", addr);
 290        test("2d48d6fc7a05", "%pm", addr);
 291        test("057afcd6482d", "%pmR", addr);
 292}
 293
 294static void __init
 295ip4(void)
 296{
 297        struct sockaddr_in sa;
 298
 299        sa.sin_family = AF_INET;
 300        sa.sin_port = cpu_to_be16(12345);
 301        sa.sin_addr.s_addr = cpu_to_be32(0x7f000001);
 302
 303        test("127.000.000.001|127.0.0.1", "%pi4|%pI4", &sa.sin_addr, &sa.sin_addr);
 304        test("127.000.000.001|127.0.0.1", "%piS|%pIS", &sa, &sa);
 305        sa.sin_addr.s_addr = cpu_to_be32(0x01020304);
 306        test("001.002.003.004:12345|1.2.3.4:12345", "%piSp|%pISp", &sa, &sa);
 307}
 308
 309static void __init
 310ip6(void)
 311{
 312}
 313
 314static void __init
 315ip(void)
 316{
 317        ip4();
 318        ip6();
 319}
 320
 321static void __init
 322uuid(void)
 323{
 324        const char uuid[16] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
 325                               0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
 326
 327        test("00010203-0405-0607-0809-0a0b0c0d0e0f", "%pUb", uuid);
 328        test("00010203-0405-0607-0809-0A0B0C0D0E0F", "%pUB", uuid);
 329        test("03020100-0504-0706-0809-0a0b0c0d0e0f", "%pUl", uuid);
 330        test("03020100-0504-0706-0809-0A0B0C0D0E0F", "%pUL", uuid);
 331}
 332
 333static struct dentry test_dentry[4] __initdata = {
 334        { .d_parent = &test_dentry[0],
 335          .d_name = QSTR_INIT(test_dentry[0].d_iname, 3),
 336          .d_iname = "foo" },
 337        { .d_parent = &test_dentry[0],
 338          .d_name = QSTR_INIT(test_dentry[1].d_iname, 5),
 339          .d_iname = "bravo" },
 340        { .d_parent = &test_dentry[1],
 341          .d_name = QSTR_INIT(test_dentry[2].d_iname, 4),
 342          .d_iname = "alfa" },
 343        { .d_parent = &test_dentry[2],
 344          .d_name = QSTR_INIT(test_dentry[3].d_iname, 5),
 345          .d_iname = "romeo" },
 346};
 347
 348static void __init
 349dentry(void)
 350{
 351        test("foo", "%pd", &test_dentry[0]);
 352        test("foo", "%pd2", &test_dentry[0]);
 353
 354        test("romeo", "%pd", &test_dentry[3]);
 355        test("alfa/romeo", "%pd2", &test_dentry[3]);
 356        test("bravo/alfa/romeo", "%pd3", &test_dentry[3]);
 357        test("/bravo/alfa/romeo", "%pd4", &test_dentry[3]);
 358        test("/bravo/alfa", "%pd4", &test_dentry[2]);
 359
 360        test("bravo/alfa  |bravo/alfa  ", "%-12pd2|%*pd2", &test_dentry[2], -12, &test_dentry[2]);
 361        test("  bravo/alfa|  bravo/alfa", "%12pd2|%*pd2", &test_dentry[2], 12, &test_dentry[2]);
 362}
 363
 364static void __init
 365struct_va_format(void)
 366{
 367}
 368
 369static void __init
 370struct_clk(void)
 371{
 372}
 373
 374static void __init
 375large_bitmap(void)
 376{
 377        const int nbits = 1 << 16;
 378        unsigned long *bits = kcalloc(BITS_TO_LONGS(nbits), sizeof(long), GFP_KERNEL);
 379        if (!bits)
 380                return;
 381
 382        bitmap_set(bits, 1, 20);
 383        bitmap_set(bits, 60000, 15);
 384        test("1-20,60000-60014", "%*pbl", nbits, bits);
 385        kfree(bits);
 386}
 387
 388static void __init
 389bitmap(void)
 390{
 391        DECLARE_BITMAP(bits, 20);
 392        const int primes[] = {2,3,5,7,11,13,17,19};
 393        int i;
 394
 395        bitmap_zero(bits, 20);
 396        test("00000|00000", "%20pb|%*pb", bits, 20, bits);
 397        test("|", "%20pbl|%*pbl", bits, 20, bits);
 398
 399        for (i = 0; i < ARRAY_SIZE(primes); ++i)
 400                set_bit(primes[i], bits);
 401        test("a28ac|a28ac", "%20pb|%*pb", bits, 20, bits);
 402        test("2-3,5,7,11,13,17,19|2-3,5,7,11,13,17,19", "%20pbl|%*pbl", bits, 20, bits);
 403
 404        bitmap_fill(bits, 20);
 405        test("fffff|fffff", "%20pb|%*pb", bits, 20, bits);
 406        test("0-19|0-19", "%20pbl|%*pbl", bits, 20, bits);
 407
 408        large_bitmap();
 409}
 410
 411static void __init
 412netdev_features(void)
 413{
 414}
 415
 416static void __init
 417flags(void)
 418{
 419        unsigned long flags;
 420        gfp_t gfp;
 421        char *cmp_buffer;
 422
 423        flags = 0;
 424        test("", "%pGp", &flags);
 425
 426        /* Page flags should filter the zone id */
 427        flags = 1UL << NR_PAGEFLAGS;
 428        test("", "%pGp", &flags);
 429
 430        flags |= 1UL << PG_uptodate | 1UL << PG_dirty | 1UL << PG_lru
 431                | 1UL << PG_active | 1UL << PG_swapbacked;
 432        test("uptodate|dirty|lru|active|swapbacked", "%pGp", &flags);
 433
 434
 435        flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC
 436                        | VM_DENYWRITE;
 437        test("read|exec|mayread|maywrite|mayexec|denywrite", "%pGv", &flags);
 438
 439        gfp = GFP_TRANSHUGE;
 440        test("GFP_TRANSHUGE", "%pGg", &gfp);
 441
 442        gfp = GFP_ATOMIC|__GFP_DMA;
 443        test("GFP_ATOMIC|GFP_DMA", "%pGg", &gfp);
 444
 445        gfp = __GFP_ATOMIC;
 446        test("__GFP_ATOMIC", "%pGg", &gfp);
 447
 448        cmp_buffer = kmalloc(BUF_SIZE, GFP_KERNEL);
 449        if (!cmp_buffer)
 450                return;
 451
 452        /* Any flags not translated by the table should remain numeric */
 453        gfp = ~__GFP_BITS_MASK;
 454        snprintf(cmp_buffer, BUF_SIZE, "%#lx", (unsigned long) gfp);
 455        test(cmp_buffer, "%pGg", &gfp);
 456
 457        snprintf(cmp_buffer, BUF_SIZE, "__GFP_ATOMIC|%#lx",
 458                                                        (unsigned long) gfp);
 459        gfp |= __GFP_ATOMIC;
 460        test(cmp_buffer, "%pGg", &gfp);
 461
 462        kfree(cmp_buffer);
 463}
 464
 465static void __init
 466test_pointer(void)
 467{
 468        plain();
 469        symbol_ptr();
 470        kernel_ptr();
 471        struct_resource();
 472        addr();
 473        escaped_str();
 474        hex_string();
 475        mac();
 476        ip();
 477        uuid();
 478        dentry();
 479        struct_va_format();
 480        struct_clk();
 481        bitmap();
 482        netdev_features();
 483        flags();
 484}
 485
 486static int __init
 487test_printf_init(void)
 488{
 489        alloced_buffer = kmalloc(BUF_SIZE + 2*PAD_SIZE, GFP_KERNEL);
 490        if (!alloced_buffer)
 491                return -ENOMEM;
 492        test_buffer = alloced_buffer + PAD_SIZE;
 493
 494        test_basic();
 495        test_number();
 496        test_string();
 497        test_pointer();
 498
 499        kfree(alloced_buffer);
 500
 501        if (failed_tests == 0)
 502                pr_info("all %u tests passed\n", total_tests);
 503        else
 504                pr_warn("failed %u out of %u tests\n", failed_tests, total_tests);
 505
 506        return failed_tests ? -EINVAL : 0;
 507}
 508
 509module_init(test_printf_init);
 510
 511MODULE_AUTHOR("Rasmus Villemoes <linux@rasmusvillemoes.dk>");
 512MODULE_LICENSE("GPL");
 513